Among various technologies available for measuring pressures within the frame of medical investigations or diagnostic methods the Pressure Profile Sensor Method has been developed recently (PPS-Method). U.S. Pat. No. 6,459,972 of Sep. 17, 2002 and the literature cited therein provide detailed information concerning the fundamentals of that technique and its potential uses.
The basis of that highly performing technique is linked to the deformation of the shape of a saline solution caused by an external pressure when applied to the catheter lumen in which the saline solution is located; of course provided the walls of the catheter tubing in which the saline solution is filled in are thin enough to be deflected by the external pressure. As the saline solution is electrically conducting, the impedance of the saline solution will change when the shape is changed through the applied pressure along the axis of the tubing and over time, the most sensitive part of the saline solution column being the front of same. So variations of the pressure can be followed over time. As performed this method provides one-dimensional pressure profiles only.
When two- or more-dimensional pressure distribution measurements are necessary this can be performed using a plurality of tubes which are arranged in parallel, each of one being successively filled with the saline solution and then subjected to electrical excitation and eventually signal detection and integration typical of the PPS-Method referred to here above. Such a way, however, is not easy to implement in human or animal body vessels or tracts, moreover slow and complex in respect of results interpretation.
Consequently the medical community is still looking for easier and more reliable methods, especially when multi-dimensional pressure distribution in various tracts or cavities of e.g. the human body are necessary. The present invention provides a very efficient solution which easily overcomes all the obstacles currently met.